Assistant professor receives NIH R21 grant for $407,000

FOR IMMEDIATE RELEASE: February 7, 2017

BATON ROUGE, LA— Michael Behnke, BSc, PhD, assistant professor in the Department of Pathobiological Sciences (PBS)
at the LSU School of Veterinary Medicine (LSU SVM), has recently been awarded a National
Institute of Health (NIH) R21 grant for his project, entitled “Large farm and small
companion animal intestinal organoids as platforms for parasite enteric development.”
The award is for $407,000 for two years.

Dr. Behnke’s research study focuses on the parasites Toxoplasma gondii and Cryptosporidium parvum that can infect and cause disease in humans. Presently, there are no robust cell
culture platforms for studying the gastrointestinal (enteric) stages of these parasites,
in large part because techniques to grow intestinal epithelial cells in the lab have
been lacking.

"This grant is key to allowing us to continue the work we have started here at the
LSU School of Veterinary Medicine,” said Dr. Behnke. “It will help us to understand
more about how medically relevant parasites establish infections and develop in the
intestine."

Recently, methods have been developed within the research community to continuously
grow intestinal crypt organoids (enteroids) from human and mouse tissue. Dr. Behnke
has adapted this technology to isolate and grow enteroids from various large farm
and small companion (LF/SC) animals that serve as definitive hosts for parasites.
These “mini-guts” have expanded over time and have been propagated to high passage
number. The LF/SC enteroids will be characterized for the presence of Lgr5+ crypt
cells and other intestinal cell linages, and will be used to develop a 2D growth platform
for use in parasite infection and differentiation assays. The ability to grow and
maintain LF/SC enteroid cell lines in tissue culture provides additional models for
the study of gastrointestinal developmental biology as well as platforms for the study
of host-pathogen interactions between intestinal cells and zoonotic pathogens of medical
importance.

Project Summary

The parasites Toxoplasma gondii and Cryptosporidium parvum can infect and cause disease in humans, each with specific pathogenesis etiologies.
Currently, there are no in vitro platforms for studying the enteric stages of these
parasites, in large part because robust methods to expand intestinal epithelial cells
from animals that are definitive hosts for these parasites have been lacking. Recently,
methods were developed to continuously grow intestinal crypt organoids from human
and mouse tissue. We have adapted these methods to isolate and grow intestinal crypt
organoids from various large farm and small companion animals that serve as definitive
hosts for parasites. These cell lines have expanded over time and have been propagated
to high passage number. We intend to characterize these lines for the presence of
Lgr5+ crypt cells and other intestinal cell linages, and to develop a 2D growth platform
for use in parasite infection and differentiation assays.

First photo: Dr. Micheal Behnke

Second photo: A cow enteroid, "mini-gut", grown in tissue culture. The mini-guts
are seeded in a 3D matrix with media containing growth factors that induce the propagation
of crypt stem cells. This enteroid has been stained to show cell membranes (green)
and regions of active growth (pink).

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